Ryan Giggs, a footballer associated with grace, poise and muscular suppleness, is attempting to teach me (associated with none of the above) the art of yoga and it is the quiet persistence of his attempts to get me to "pull up from the obliques" for a third time that reveals how different a manager he will be, one day, from the one for whom he has performed 599 times in the league ahead of this weekend's trip to Tottenham.

Sarah Ramsden, the yoga professional who has done so much for Giggs and is leading this session, warns in her preamble that "if you've stopped breathing you've gone too far," which sounds rather ominous, though Giggs does not seem to require oxygen as he flattens his spine against his yoga mat and eases up his legs.

"You don't need to touch your toes if you're feeling the hamstring," Giggs tells me quietly and diplomatically, when we've moved into the next series of stretches. When he instructs me to turn my head without moving the hips, the unmistakable sight of his agent, Harry Swales, looms into view. Swales is 84 and has skipped the session. "I thought I'd leave you to it," he says, grinning from behind his vast and distinctive handlebar moustache. Giggs neglects to say that Swales would have been a more able pupil.

Giggs is here to discuss the new DVD on which he and Ramsden have collaborated, which provides an insight into the mixture of yoga, Pilates and conditioning work without which we would not be witnessing the winger standing on the cusp of two more of those landmarks which seem to litter each of his seasons: the 600th league appearance, if he plays a part at White Hart Lane tomorrow, will be followed in a little over a month by the 20th anniversary of the cold spring day when he first appeared for United.

The career progression across the decades seems so elementary and effortless now, though it was not like that on a bitterly cold night in Munich, on 19 November 2001, when an ill-fated training session pushed Giggs towards yoga. It was in the old Olympic Stadium, ahead of United's Champions League tie with Bayern, where Giggs, now 37, sustained another of the series of hamstring injuries which were causing so much devastation in the middle part of his career and which, on that occasion, forced him to reappraise every aspect of his life.

"I would have been playing in that match," Giggs recalls. "The manager had already told me I was playing. It was the day before the game, we were training at the stadium and it was just coming towards the end of the session when it happened. It was cold – that didn't help – and right at the end I'd gone on a jinking run when I felt my hamstring. I was just so depressed it was unbelievable. I remember going back to the hotel and sitting there, gutted. I had travelled over and trained, I was feeling good and suddenly I'm missing out, which is something that shouldn't happen.

"It was that day I just thought: 'I need to do something, I need to not drink as much alcohol, I need to look at my diet, I need to do everything I can, my bed, cars – everything to stop this happening.' The hamstring injuries were stopping me probably playing 10 or 15 games a season and I was coming up to 30."

The mattress was the easy bit and the car, after a little soul-searching, relatively straightforward. (Giggs settled for a Mercedes 500, rather than buy a new sports car each year, with the stiff clutches that put extra stress on his left leg and hamstrings.) But the yoga was something he hardly knew was there. A yoga practitioner, remembered only as "Louise" by United players of the time, had started work a fortnight earlier at the club's new Carrington training complex. "The physio had brought her in," Giggs recalls. "I was just looking at any angle so I just wandered over to her, talked to her, told her my problems and she just said: 'Yeah, come next week then.'"

Giggs wasn't the only intrigued United player. Roy Keane, Gary Neville and Mikaël Silvestre all started yoga at about the same time in the hope that muscular suppleness might extend their careers. Silvestre may be the less illustrious player of that quartet, but the relish with which he took to the discipline was typical of the French players who have always been years ahead of the British in this field.

"Mikaël was like a yoga teacher," Giggs says. "Foreign and British players have the same approach to coming in and doing yoga. But, from my experience, you see players who come from France they have got better flexibility because they are taught to stretch; it's a massive part of their game from a young age. They have just got more flexibility, or they seem to. It's part of what they do – whereas British players stretching is just something that you either do wrong or you are sat around pretending to stretch, having a chat just before you go out to train."

The consequences have been profound for Giggs. The hamstrings are not immune – he played only three games in two months through last autumn because of a hamstring injury sustained at Bolton and aggravated against West Bromwich Albion – and he provides a revealing insight into the anxiety which players prone to injury take into every game when he reflects on the fact that he has not run flat out in a match since sustaining his first injury, in a league encounter with Ipswich Town in the early 1990s.

"I'd say I haven't sprinted since I was 19, 20 or 21 at full pace because I was always wary of my hamstrings since that first calf injury. How old would I have been? Twenty? Up to then I'd had no injuries, but once you get that first hamstring injury you are always wary of sprinting full pelt."

Needless to say, Giggs did not imagine when he made the mental decision to play within himself that he would one day eclipse Sir Bobby Charlton by turning out in comfortably more games in all competitions for United than any other player – and do so by opting for yoga. Back in those early days at The Cliff, stretching hardly came into it. "Training would start at 10.30am so I'd be there at twenty past ready to go," he recalled in a recent interview with Men's Health magazine, whose interest in Giggs reveals everything about the way he has carried a torch for new forms of physical preparation. "There would be a lot of football, no gym work at all. We'd finish at midday, have lunch and I'd be home by half past 12."

These days he is in at 8.30am – Ramsden was driving through the Carrington gates before that yesterday – and doesn't leave until 2pm. That debut day at Old Trafford – Giggs appearing as a late substitute for Denis Irwin in a 2-0 home defeat to Everton on 2 March 1991 – is one which will be replayed on a loop in the weeks with the 20th anniversary looming. Giggs seems surprised when told of it – "I was wondering where you were going there," he says, when the question is out. "I was aware it was coming up to 20 years but I didn't know when" – and his recollections are certainly not as muscular as he is, where that otherwise rather grim afternoon is concerned. United were in desperate form, missing Bryan Robson, Steve Bruce, Neil Webb and Mark Hughes through injury, and it was as a strike partner for Danny Wallace – Giggs never shared Sir Alex Ferguson's initial belief that he could be a front man, feeling he lacked technical finishing ability – that he was sent on, to do his best on a dreadful playing surface which was half sand, half ankle-deep mud.

"I've watched that game recently and it struck me how little of it I remember – not a thing," Giggs says. "I remember crossing a ball for Danny Wallace, he got a header in and it went just wide and feeling quite chuffed about myself. I remember Dave Watson going right through the back of me, it was a 'welcome to the big boys'. I had a mark down my knee where he had studded me. It wasn't dirty, though you couldn't get away with it now – just one of those things I suppose."

It is while searching back through his mental encyclopedia that another memory of the game comes to mind. "I went through and I was against [Everton goalkeeper] Neville Southall and I sort of like tried to knock it and it was 50-50 and he's got there first and I've just gone tumbling." It is his full debut in the Manchester derby against City at Old Trafford two months later, in which Giggs was credited with a goal deflected in off Colin Hendry, that he recalls best.

Fittingly, the 600th appearance will coincide with evidence in north London of another player blessed with powers of longevity. David Beckham will not appear for Tottenham against United but that is not the point of his value to Spurs, Giggs reflects. "He's been away eight years but he has still got that quality of producing a cross, a free-kick or goal. It will be great for the Tottenham players, especially the younger players, to see the professionalism of him, how he conducts himself. The thing about Becks is he has always prepared himself right."

And with that Giggs is away. Not to a wholly yogic domestic life, it should be said – there's no yogic flying at home in Worsley and the culinary and spiritual parts of yoga don't come into things either. "We have everything laid out for us, foodwise [at United], and that side of it is not what interests me really." The absorbing part, as he puts it, is "just being able to train every day and feeling good." Which, the morning after "pulling up from the obliques" is not a description of your correspondent, with or without Giggs as a mentor.

Ryan Giggs, a Reebok ambassador, was speaking at the launch of 'Giggs Fitness', a new strength and conditioning workout DVD which is inspired by yoga and offers expert advice. For more information or to purchase 'Giggs Fitness', visit www.amazon. co.uk or www.giggsfitness.com